Characteristics of placebo response during long-term treatment of panic disorder.
Mixed-panic disorder patients (16/60, 27%) randomly assigned to receive blind placebo during a 40-week treatment study were defined as placebo responders based on combined criteria of Hamilton Anxiety Scale score percentage decreases below the median point (-42%), moderate to marked improvement on both clinician and patient Clinical Global Impressions scores, and panic-free at final treatment visit. These criteria applied separately also resulted in a similar clinical grouping and pattern of response. Differential patterns of response between responders and nonresponders occurred across most clinical measures of panic/anxiety. Responders experienced early improvement within the first week of double-blind treatment. This response progressed during treatment and tended to persist during taper and at followup 1 month later. Post-hoc analysis of demographic and clinical features at entrance into the study failed to characterize this stringently defined group of placebo responders.
Dager
S R
SR
Harborview Medical Center, Seattle, WA 98104.
Khan
A
A
Cowley
D
D
Avery
D H
DH
Elder
J
J
Roy-Byrne
P
P
Dunner
D L
DL
D000328:Adult; D000525:Alprazolam / Q000627:therapeutic use; D001008:Anxiety Disorders / Q000188:drug therapy* / Q000523:psychology; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010200:Panic; D010919:Placebos / Q000627:therapeutic use*; D011569:Psychiatric Status Rating Scales; D013997:Time Factors
D010919:Placebos; D000525:Alprazolam